PT/INRProthrombin time and INR
What it shows
How fast the blood clots. People on warfarin check their INR regularly.
Your doctor reads the result: the laboratory does not diagnose or prescribe. The result sheet gives the reference range beside each value.
Sample
- Short code
- PT/INR
- What is taken
- Blood from a vein
- Container
- Blue-top citrate tube
- Turnaround
- Same day at 18:00, for samples taken by 12:00
- At home
- Yes, a nurse comes to your home
Preparation
- 8 hours after your last meal, on an empty stomach. Water is fine.
- If you take warfarin, heparin or another blood thinner, tell us the dose and when you took it.
- No hard exercise the day before.
Reference ranges
| For | Range |
|---|---|
| Everyone | 0.85–1.15 INR |
These ranges are for Damla’s analysers and methods; another laboratory’s ranges may differ slightly.
From the same section
- APTTActivated partial thromboplastin time (APTT)₼12
- FIBFibrinogen₼12
- D-dimerD-dimer₼30
- COAGCoagulation panel: PT/INR, APTT, fibrinogen, thrombin time₼40